6.2l Vortec Hole In Piston

cooperg · July 19, 2011

Hey guys, just wondering if anyone's heard of someone putting a hole in a piston on the L92 Vortec. I have an 09 Sierra Denali with 70 000 km (43500 miles) and as of yesterday, I apparently have a hole in one piston. I have an airaid intake and a Bully Dog triple dog GT programmer in it. Because of this GM won't warranty this fix.

Anyone else have a similar problem? Any insight to it? The dealer said it got overfueled and too hot...which doesn't make sense at all. For that to happen it would have to be running lean would it not?

ANY HELP ON THIS ASAP WOULD BE GREAT. I think I will be in a heated discussion with the dealer the next couple days.

greentourismo · July 19, 2011

im sure they meant lean condition...service writers arent very smart, even tho they think they are mechanics

Hey guys, just wondering if anyone's heard of someone putting a hole in a piston on the L92 Vortec. I have an 09 Sierra Denali with 70 000 km (43500 miles) and as of yesterday, I apparently have a hole in one piston. I have an airaid intake and a Bully Dog triple dog GT programmer in it. Because of this GM won't warranty this fix.

Anyone else have a similar problem? Any insight to it? The dealer said it got overfueled and too hot...which doesn't make sense at all. For that to happen it would have to be running lean would it not?

ANY HELP ON THIS ASAP WOULD BE GREAT. I think I will be in a heated discussion with the dealer the next couple days.

cooperg · July 19, 2011

They said "thats how these programmers get more power, they increase the amount of fuel injected and the overfueling caused the hole" ....

hrspwr · July 19, 2011

Holes in pistons are the total opposite. Overfueling will foul plugs and over time wash the cylinder walls. Lean and detonation will cause a hole to form. With the program did you play around with timing? Did you run a lower grade of fuel then what the program wanted?

ChevyTech77 · July 19, 2011

They said "thats how these programmers get more power, they increase the amount of fuel injected and the overfueling caused the hole" ....

On a diesel engine, they would be correct.

What grade fuel have you been running? 87 is a no no with a stock tune let alone anything aftermarket. Add to that a decent load and time and yeah, I could see it burning a piston.

redjewel2ss · July 19, 2011

revert back to your stock tune, re-install the stock intake and take it to another dealership!

Z45 · July 19, 2011

Too late, its in the system and the powertrain warranty may now be gone. The fact the dealer knows it is enough, that's GM policy and dealer hands are tied. GM won't approve any repairs on engines that are chipped.

According to my dealer, any hard parts must be approved by the zone service manager and the dealer cannot just replace hard parts without that approval code.

If a suspicious hard part failure is observed in the engine, transmission, transfer case, or driveline, perform the calibration verification described to determine if a non GM issued engine calibration is installed. Non GM issued engine calibrations subject driveline components to stresses different than those that these components were validated to. Repairs to transmission, transfer case and / or other driveline components where a non GM engine calibration has been verified, are not covered under the terms of the New Vehicle Warranty.

Stevens03 · July 19, 2011

Not to sound like a bonehead, but you took the risk knowing you could loose your warranty

mkelly · July 19, 2011

Your piston has a hole in it because of faulty ecu programming..... and I would bet that the bully dog is the culprit.

After you buy your new engine out of pocket you might think twice about adding the programmer

Stevens03 · July 19, 2011

I'd think a combination of Bully dog and the air intake. I'm told the 6.2L do not like Cold air intakes and cause them to lean out. If a cold air intake is installed, you need to have the PCM updated to see any gains. If you don't, you can actually have a loss of power.

I'd bet the combined 2 mods were at fault. Or just a defective piston to begin with and the programmer/intake helped bring the issue out.

markw8 · July 19, 2011

Factory tunes tend toward the rich side. Runs cooler and doesn't burn pistons. The most power is made with a leaner mixture just short of ping/detonation.

Mark

temmert1 · July 19, 2011

I'd think a combination of Bully dog and the air intake. I'm told the 6.2L do not like Cold air intakes and cause them to lean out. If a cold air intake is installed, you need to have the PCM updated to see any gains. If you don't, you can actually have a loss of power.

I'd bet the combined 2 mods were at fault. Or just a defective piston to begin with and the programmer/intake helped bring the issue out.

Have to admit this scares me....... Why do you say the 6.2L does not like the CAI? I actually asked Jusitn a week before the tune if I should take it off and go back to stock air box. He said to leave it on.......HMMMM>>>>

mhenshaw · July 19, 2011

I'd think a combination of Bully dog and the air intake. I'm told the 6.2L do not like Cold air intakes and cause them to lean out. If a cold air intake is installed, you need to have the PCM updated to see any gains. If you don't, you can actually have a loss of power.

I'd bet the combined 2 mods were at fault. Or just a defective piston to begin with and the programmer/intake helped bring the issue out.

Please explain how an cold air intake could lean out a EFI motor. Doesn't the MAF sensor and O2 sensors compensate for any change in the air coming in? The computer would adjust if it sensed the motor had too much air.

Factory tunes tend toward the rich side. Runs cooler and doesn't burn pistons. The most power is made with a leaner mixture just short of ping/detonation.

Mark

+1 gas burners get more power by running on the lean side which hurts the motor. The sevice people are thinking about diesel trucks that you add fuel to make power.

HawkScot · July 19, 2011

Sorry to hear of your problems.. I think your GM warranty is already toast, but perhaps Bully Dog will stand behind their product (unless you changed the programming or didn't follow their guidelines).

Stevens03 · July 19, 2011

I'd think a combination of Bully dog and the air intake. I'm told the 6.2L do not like Cold air intakes and cause them to lean out. If a cold air intake is installed, you need to have the PCM updated to see any gains. If you don't, you can actually have a loss of power.

I'd bet the combined 2 mods were at fault. Or just a defective piston to begin with and the programmer/intake helped bring the issue out.

Have to admit this scares me....... Why do you say the 6.2L does not like the CAI? I actually asked Jusitn a week before the tune if I should take it off and go back to stock air box. He said to leave it on.......HMMMM>>>>

Yeah, Justin can tune for it.. but without a tune it can be an issue....Justin was the one that told me. Unless I understood him wrong The 6.2L were the ones that didn't "like it" when you messed with the air intake tube size. Others aren't as vulnerable.